IF he's like me, he has a 4-button comfort control and a control box.
You'll need to tell us what you've got in there now... There are a ton of possible combinations.
The install docs for your unit are generic across several, but they're available here:
box instructions are separate, but on the underside of your unit you can see compatible systems listed. If you need an analog control and a an interior dial-control, I've got a brand new one that I'm not going to use with a a ducted system.